EUVE: New Postings
During the first 6 months of its mission, EUVE carried out a survey of
the entire sky in 4 filter bandpasses covering the wavelength region
of 58-742 Angstroms. This dataset (originally distributed on 3 CD-Roms
produced by the CEA in 2000) collects together the raw photon,
exposure, and exposure-corrected photon sky maps for all survey
bandpasses in the form of three-dimensional data cubes in FITS format.
A more complete description of these data is available
here. (Posted 2004 May 19).
EUVE SPACECRAFT RE-ENTERS EARTH'S ATMOSPHERE
The following is taken from the
"NASA's Extreme Ultraviolet Explorer (EUVE) re-entered the Earth's atmosphere
at approximately 11:15 p.m. EST Wednesday. According to calculations made
by the United States Space Command Space Control Center, EUVE re-entered the
atmosphere over central Egypt. Using U.S. Space Command data,
engineers calculated EUVE's orbit track and predicted where it could
re-enter the atmosphere. EUVE did not have an on-board propulsion system
to allow engineers to control the spacecraft's re-entry. EUVE was in a
28.5-degree orbit and could re-enter in any location within this orbit range.
This range included areas as far north as Orlando, Fla., and as far
south as Brisbane, Australia. The object was not designed to survive re-entry
intact and was expected to break apart and mostly burn up in the
atmosphere. U.S. Space Command cannot confirm if any pieces survived re-entry."
(Posted 2002 January 31).
AGING NASA SPACECRAFT TO REENTER EARTH'S ATMOSPHERE
is the headline
of the NASA News
and EUVE is the spacecraft!
"Engineers at NASA Goddard Space Flight Center in Greenbelt, Md., predict a
7,000-pound spacecraft could re-enter the Earth's atmosphere as early as 10
p.m. EST on Jan. 30 or as late as 7 a.m. EST on Jan. 31. NASA's Extreme
Ultraviolet Explorer (EUVE) is currently 200 kilometers (124 miles) above the
Earth with a descent rate of 25 kilometers (15.5
miles) a day. The estimated debris field is expected to be 800 to 1,000
kilometers (500-625 miles). "The probability of the few EUVE surviving
pieces falling into a populated area and hurting someone is very small. It
is more likely that the small pieces will fall into the ocean or fall
harmlessly to the ground," said Ronald E. Mahmot, Project Manager for
Space Science Mission Operations at Goddard." (Posted 2002 January 29).
A guide to the EUVE Science Archive Data Products which was put
together by the Center for Extreme-Ultraviolet Astrophysics (CEA) is
available for download.
Mark Abbott of CEA wrote this document which contains a summary
description of the EUVE Science Archive pointed products. It is meant to
be used as a supplement to the older EUVE Software Users' Guide and
EUVE Data Products Guide. The Science Archive Data Products is
available at the HEASARC ftp site in both PDF format
(129 Kb) and PostScript
format (965 Kb). (Updated 2001 December 7).
The HEASARC Archive of EUVE pointing-mode spectroscopic observations is
now complete and all datasets are publically available
On October 1, 2001 the last proprietary EUVE datasets became public.
All EUVE pointing-mode spectroscopic observations are
available in the HEASARC's anonymous
These new observations are most easily available using the the EUVEMASTER
Catalog that is available via the Web
interface. (Updated: 2001 October 9).
The Center for Extreme Ultraviolet Astronomy (CEA) is now
closed, including the ftp and Web sites
On March 27 2001, the CEA ftp and Web sites
were closed down, although some of the Web
pages were moved to the main UC Berkeley
Space Sciences Laboratory
Web site. The HEASARC copied the contents of the CEA ftp and
Web sites over before they closed and is in the
process of re-organizing its own EUVE ftp area
and Web pages to incorporate this material.
(Posted 2001 March 27).
Final EUVE Calibration Observation Results
A report on
a final series of calibration observations made with the EUVE Satellite
is now available. The stars selected were the usual EUVE calibration
targets HZ 43 (spectrometer) and GD 153 (scanner) for throughput, and
Capella for the wavelength solution. The observations were made
between 9-16 January 2001, during the last month of EUVE operations.
(Posted 2001 March 27).
EUVE Operations are Ended
In the summer of 2000, NASA decided that EUVE mission operations should cease
within a few months. EUVE science operations ended on January 26, 2001, and
there followed several days of end-of-life mission engineering tests of the
never-used backup high voltage supplies and checking of the remaining battery
capacity. EUVE was stabilized pointing away from the Sun and sent into
safehold at 23:59 UTC on Jan 31 2001. The transmitters were finally commanded
off on Feb 2 2001. EUVE is now in a 424 x 433 km x 28.4 deg orbit and will
probably reenter sometime in 2002. (Posted 2001 February 6).
(Posted 2000 November 21).
Late in 1997, NASA decided that the EUVE final data archive responsibilities
should be transferred from the Center for Extreme-Ultraviolet Astrophysics
to the HEASARC, the
Multi-Mission Archive at the Space Telescope (MAST)
, and the
National Space Sciences Data Center (NSSDC)
. The HEASARC's
role is to serve the EUVE data and act as an interface for the community of
high-energy (X-ray and gamma-ray) astrophysicists, the STScI's is to provide
similar access to the optical and UV community and to maintain the EUVE IRAF
based software package, while the NSSDC's role is to act as a deep archive for
EUVE data and to service requests for large amounts of data, i.e., for amounts
of data that are infeasible to retrieve over the Internet/WWW.
What EUVE datasets does the HEASARC have?
- The datasets that were on the 6 CD-ROMs issued by CEA in 1993 have
been taken offline as they have been superceded by the data in the primary
- The EUVE
Stellar Spectral Atlas" of Craig, N., Abbott, M., Finley, D., Jessop, H.,
Howell, S.B., Mathioudakis, M., Sommers, J., Vallerga, J.V., and Malina, R.F.
which was published in 1997 in ApJS, vol. 113, pp. 131 et seq. They comprise
FITS and PostScript versions of the EUVE spectra of 95 bright stellar sources
which were observed by EUVE, grouped by the type of source, together with
some supporting material.
- The EUVE Spectrometer Pointed Science data (aka the EUVE Science Archive)
in the form of
events and image files
in FITS format.
All files are now in the public domain.
To find out which targets have been observed by EUVE in pointed mode,
it is most convenient use the HEASARC Web
interface to search the EUVEMASTER database.
- The all-sky maps made by the EUVE Scanning Telescopes using 4 filters
covering the range from 50 to 740 Angstroms are available through the
- Notice that the Level 0 (telemetry) data are not archived at
the HEASARC, but that the NSSDC maintains a copy of
What is the easiest way to select the desired EUVE datasets?
- The Science Archive Data (the main archive of EUVE Spectrometer Pointed
`science data') is most easily accessible using the HEASARC's
- Alternatively, the user can examine
Anonymous ftp archive at legacy.gsfc.nasa.gov, the directory
euve/data/fits, and list the contents using either the 'ls' or 'dir'
command. This listing will list the various sub-directories (one for each
unique target) using symbolic links based on the target names listed by the
CEA, e.g., the sub-directory alpha_cen contains the files containing the EUVE
observations of the target Alpha Cen. The file names themselves were created
by the HEASARC based on the target name and the date and time of the
observation, e.g., alpha_cen__9305291354N_evt.fits.gz is the gzipped
FITS-format events file for the observation of Alpha Cen which started on
1993 May 29 at 13:54 UT which contains events detected during spacecraft
night (N). Once you have identified the file or files of interest,
then use the 'get' or 'mget' command to copy over the desired
files (set the ftp transfer protocol to binary, remember, for FITS files).